1. Field of the Invention
The present invention relates, in general, to an adhesive transfer ink which is used in patterning a mold or a substrate and, more particularly, to a UV-curable, adhesive transfer ink which can be cured by UV, to serve as a mask during the etching of a molds or substrate to be embossed.
2. Description of the Prior Art
Etching is a technique for forming patterns or figures on molds or substrates, which is conventionally conducted as a single etching or multiple etching process. Typically, single etching comprises the steps of (a) pre-treating a substrate with diluted hydrochloric acid, (b) photoresist-coating, (c) photo-masking, (d) UV-irradiating, (e) developing, (f) pattern correction, (g) etching, (h) photoresist-removal and (i) surface treatment. The multiple etching process, developed to accomplish various patterns or figures on a substrate, is carried out by repeating steps (b) through (h) of the single etching process.
In the photoresist-coating step of the single or multiple etching process, photoresist is spray-coated or screen-coated on a substrate to which figures are transferred. Usually, it is difficult to uniformly coat photoresist. In the multiple etching process, an etched primary figure or pattern is coated with photoresist and the resultant is coated with a secondary figure or pattern-bearing film. At this time, however, the primary figure or pattern is not seen or exposed by the photoresist.
Also, conventional etching techniques suffer from a disadvantage in that UV is not uniformly irradiated on the surfaces of substrates or molds owing to their outward forms, so that developing defectives take place in a subsequent developing step, making it difficult to precisely form predetermined patterns or figures. When a developing defective occurs, it is necessary to correct the pattern, resulting in an increase in the number of the process steps.
In order to overcome such disadvantages, there has been introduced a water-transfer process in which, after a printing sheet bearing a predetermined pattern or figure is coated on a substrate, application of water allows the predetermined pattern or figure to transfer to the substrate. Then, the sheet is separated from the substrate and the pattern or figure remain alone. However, it is also difficult to obtain a desired pattern or figure because the printing sheet is overly sensitive to moisture.